
16.COORDINATE SYSTEM CONVERSION FUNCTION NC FUNCTIONS B-63782EN/01
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16.5 TILTED WORKING PLANE COMMAND
Programming for creating holes and pockets in a surface tilted from the
datum plane of a workpiece would be easy if commands can be issued
in a coordinate system fixed to this surface (called a feature coordinate
system). This function enables commands to be issued in the feature
coordinate system.
The feature coordinate system is defined in the workpiece coordinate
system.
See Fig. 16.5 (a) for explanations about the relationships between the
feature coordinate system and workpiece coordinate system.
Feature coordinate system
(G68.2)
Machine coordinate system
Workpiece coordinate
system (G54)
Feature coordinate system
Fig. 16.5 (a)
G68.2 selects the feature coordinate system as a coordinate system for
programming. The commands in all the subsequent blocks are assumed
to be issued in the feature coordinate system until G69 appears.
If G68.2 specifies the relationships of the feature coordinate system to
the workpiece coordinate system, G53.1 automatically specifies the +Z
direction of the feature coordinate system as the tool axis direction
even if no angle is specified for the rotary axis. (See Fig. 16.5 (c).)
See Fig. 16.5 (b) for explanations about the tool axis direction.
X
Tool axis direction
Y
Z
The tool axis direction is
the +Z-axis direction.
The tool axis direction is
the +Y-axis direction.
The tool axis direction is
the +X-axis direction.
Fig. 16.5 (b)